One new and specialized type of imaging involves the capture of low intensity light—often on the order of only tens to hundreds of photons—from a light-emitting sample. The low intensity light source may be emitted from any of a variety of light-emitting sources within a living specimen, e.g., luciferase expressing cells within a mouse. The source of the light indicates portions of the sample, such as traced molecules in a particular portion of a mammalian specimen, where an activity of interest may be taking place. Some specialized in-vivo imaging applications include analysis of one or more representations of emissions from internal portions of a specimen superimposed on a photographic representation of the specimen. The photographic representation provides the user with a pictorial reference of the specimen. The luminescence representation indicates portions of the specimen where an activity of interest may be taking place.
Obtaining a luminescence representation often involves image capture over an extended period of time, e.g., minutes, in a specialized imaging box. The imaging box is a custom-made apparatus designed to tightly control the amount of light in the box and minimize light entering from the surrounding room. The living specimen is typically anesthetized during imaging to prevent movement that may affect prolonged image capture.
An induction chamber is typically used to anesthetize the living specimen before being placed in the imaging box. A laboratory technician or researcher places one or more conscious living specimens in the induction chamber. A combination of anesthetizing gas and oxygen is then supplied to the induction chamber. The specimen remains in the induction chamber until it loses consciousness, or is similarly sedated, and is then transported by the laboratory technician into the imaging box. Transporting living specimens in and out of the induction chamber may allow the anesthesia gas to escape into the ambient surroundings. Preferably, the amount of anesthesia gas that escapes is minimized.
Conventional induction chambers rely on a purge system to manage anesthesia gas escape. The purge system forces high-pressure oxygen into the induction chamber before the door or user access is opened. A passive exhaust port leading from the induction chamber interior receives the high-pressure purge oxygen and any gases present in the induction chamber before the purge. One problem with purge systems is that the high burst of oxygen, and/or removal of all anesthetizing gas, frequently awakens any living specimens in the induction chamber. When a single living specimen is in the induction chamber, this is clearly defeating to the intended induction chamber purpose. Lab technicians however often work with multiple living specimens at a single time and purging the induction chamber to remove one specimen may then lead to more than one specimen awakening.
In view of the foregoing, an improved induction chamber capable of anesthetizing one or more living specimens would be desirable.